Treatments to reduce cocaine use have been both pharmacological based on hypothesized biological mechanisms action, and psychological, based on behavioral and cognitive-behavioral theory. Most pharmacotherapies for cocaine dependence are still in need of confirmation. During the original funding period of this grant, our research at the SAMDRC has been pivotal in identifying the role of agonist medication treatments for cocaine dependence. We have demonstrated that levodopa (L-dopa) along with carbidopa can be safely administered and has discernable efficacy over placebo in the ambulatory treatment of cocaine dependence. The optimal use of this pharmacotherapy, however, is not likely to depend on the behavioral/environment context in which the medication is administered. Cognitive-behavioral approaches and contingency management procedures are two behaviorally based therapies for cocaine addiction that have been empirically evaluated. The purpose of this research is to determine whether these two popular behavioral approaches, independently or combined, serve to enhance a promising new pharmacologic strategy. Two studies will be conducted concurrently. Study 1 will employ a randomized, between groups, additive research design, to test the hypothesis that the combination of RP and Contingency Management Procedures (CMP) can potentiate the efficacy of L- dopa/carbidopa. Three therapy conditions of varying intensity will be compared: (1) clinical management (CM) only; (2) CM+RP, and (3) CM +CMP. The incremental efficacy of these therapy conditions will be examined under active and placebo medication conditions. A total sample of 120 cocaine dependent individuals will be randomly assigned to one of the six treatment conditions. Study 2 will parametrically assess which type of contingent incentive, when compared with RP, facilities the efficacy of agonist pharmacotherapy. Participants will receive RP therapy in combination with a CMP that targets clinic attendance, medication compliance, or cocaine abstinence. A total sample of 120 cocaine dependent individuals will be randomly assigned to one of the six treatment conditions. Both studies will be conducted concurrently, using nearly identical recruitment, intake, and assessment procedures. Assignment to treatment group will be random, using an urn randomizing technique to assure balanced distribution of baseline characteristics that may influence outcome. Standard outcome variables related to cocaine (urine toxicology screens and patient self report), addiction problem severity, medication compliance, and clinic visit attendance will be collected during twelve weeks of treatment and one year follow up. Assessment of potential prognostic dimensions, including severity of cocaine dependence, concurrent alcohol use, motivation for treatment and level of readiness to change, will be used to identify patient characteristics associated with optimal outcome in these well-defined treatments. These studies are direct, logical extensions of our research on the integration of behavior therapy with promising pharmacotherapy for the treatment of cocaine dependence.